There is a compelling need in the field of optical sensors for a fast response dual band position sensor that can detect energy in two different spectral bands, are fast enough to track time varying intensities of light, and at the same time can track the location of the source of the light as that source moves at high velocities. Such a need exists for both commercial and military applications.
A variety of optical position sensors are known. Some of these include sensor systems that can locate the spot of illumination using imaging cameras, but suffer from a relatively slow response time. Some of the sensor systems sense multiple spectral bands by using multiple cameras to view the scene, with a different camera sensing each of the spectral bands. These systems are much larger and more complex, and the images they produce must be spatially aligned with each other. Because of their slow response, these imaging cameras cannot distinguish between the flashes that are characteristics of different small-caliber weapons.
Prior position sensing detectors, such as lateral-effect position sensing detectors, can have fast response and provide information on the location of a spot of light. However, these detectors cannot distinguish between multiple spectral bands. The existing sensors that cover a larger field of view often require large and slow mechanical gimbals to move their narrow field of view (FOV) detectors.